Yoshiaki Ogawa, known to everyone as Yoppa, is one of the eighteen students in Hinobori Elementary School's Earth Defense Class. His grandfather, an eccentric man deeply fascinated by airplanes, plays a pivotal role in motivating Yoppa during a critical event. Driven to prove himself and earn his grandfather's recognition, Yoppa undertakes a daring theft of the Raijin Commander, the critical technology controlling the powerful Raijin-Oh mecha.